Mixed agreement, the person feature, and the index/concord distinction

Abstract

In mixed agreement, different agreement targets show different values for the same controller. This paper offers an explanation for the existence of mixed agreement that accounts for the following Polite Plural Generalization: universally, any second person ‘polite plural’ pronouns (e.g. French vous), used honorifically for a single addressee, control syntactic (plural) agreement on all person targets, while non-person-agreeing targets such as predicate adjectives vary across languages, between syntactic and semantic number agreement. Following Wechsler and Zlatic (The Many Faces of Agreement, CSLI Publications, 2003), person features exist only as features of referential indices (Index phi features), never as grammatical head features of the sort that are involved in adjective-noun concord (Concord phi features). Mixed agreement arises if the ‘polite plural’ or other pronominal controller is underspecified for Concord phi features. But a pronoun has a referential Index, which is necessarily marked with phi features, so any Index agreement targets will appear in the second person plural form. A diachronic explanation is offered for this bifurcation of agreement targets into Index and Concord targets: the former descend from incorporated pronouns while the latter have other sources.